Complete the chemical name of the compound Col3. Use the periodic table to help form your answer. Type the correct answer in the box. Spell all words correctly. Use parentheses where appropriate.

Cobalt (III)

Explanation:

Since there is a 3 by iodine and cobalt is a transition metal it means cobalt has a 3 charge and we have to write it in roman numerals

with this one i know the answer in craters one reason i looked it up and i learned about it there is my evidence

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.